/Engine/Plugins/Runtime/MeshModelingToolset/Source/ModelingComponents/Public/BaseTools/SingleSelectionMeshEditingTool.h
the input Selection, or nullptr if one was not configured
virtual const [UDEPRECATED_PersistentMeshSelection](API\Plugins\ModelingComponents\Selection\UDEPRECATED_PersistentMeshSelect-) * GetInputSelection() const